Electromagnetic centrifugal pump



st 22, 1953 l F. E. cREvER 2,652,778

ELECTROMAGNETIC CENTRIFUGAL PUMP Filed Sept. 6. 1949 Patented Sept. 22,' 1953 :,sszms Y ansc'raoMaGNE'nc cammen rum Frederick E. Crever, Scotia. N. Y.. assigner, by meine assignments, to the United States of America as represented Atomic Energy Commissie by the United States Application September 8, 1949, Seth] No. 114,211

8 Claims. (Cl. 10S-l) The present invention relates to electromagnetic centrifugal pumps.

, One of the problems in atomic power work is that of pumping liquidA metal coolants through atomic reactors and associated heat exchangers.

Mechanical centrifugal pumps present problems of bearings operating in the coolant and of seals for the pump shafts. In order to obviate these mechanical difliculties electromagnetic pumps may be used wherein there are no moving parts.

lThe present device for pumping electrically conductive uids embodies the interaction of a xed magnetic field and a D. C. current owing through the conducting neld. Within the pump chamber a liquid metal is whirled in a spiral path about the axis of the chamber by means of the interaction of a fixed magnetic field and a D. C.

current which flows through the uid ln a direction normal to the eld and radially of the chamber, causing the liquid to move in` a third direction which is normal to the directions of the iield and current. As the liquid gains momentum, it is thrown outwardly from a central' inlet to the periphery. by centrifugal force.

The various structural features and advantages of this invention will become more apparent by reference to the accompanying drawings and the following description of a preferred embodiment thereof. In the drawings,

Figure 1 is a plan view partly in section of an electromagnetic centrifugal pump;

Figure 2 is a vertical sectional view. taken on the line 2-2 of Figure l; and

Figure 3 illustrates two pumps connected in series in a closed system of the liquid metal.

As shown ln Figure 2 the pump is generally indicated at I2. An annular.` magnetic member I2 constitutes the lower portion of the pump Il. In the central opening of the annular member I2 is an inlet pipe I4 which is separated from the annular member I2 by an air gap Il. The pipe I4 is open at its upper extremity and flared at II. The top portion of the pump is a circular magnetic member which r'ests on the annular magnetic member I2 at the peripheral interface 22 and which is secured thereto by means of.

bolts 24.

A flat circular chamber 24 is disposed horizontally between the magnetic members I2 and 24. 'Ihe chamber. 28 is insulated from said members 24 and I2 by means of walls 24 and 2l, respectively. which are ceramic insulators. The

upper wall 2l is a circular disk and the lower wall 2l is an annular body. At the center of the annular wall 2l is an opening 22 where the flared extremity Il of the inlet pipe I4 is sealed to the wall.

About the periphery of the chamber 24 is an enlarged portion 24 which is formed by an annular housing 22 and which communicates with the chamber 24. The Amember 24 is composed of. electrically conductive material and is sealed at 4l and 4l to the ceramic material of the walls 28 and 2l, respectively. Surrounding the housing 28 is an air gap 42 which insulates it from the magnetic members 24 and I2. As shown in Figure l, tangential outlet pipe 44 is attached at the periphery of the housing Il at 44. Below the housing 2B is an annular channel 44 in the magnetic me .nber I2. The channel 44 is a receptacle for windings 50, which are simply laid in place. Between the windings and the housing 26 is padding II.

'I'he electrical potential for the pump is supplied by a D. C. supply not shown in the drawings. Referring to Figures l and 2 a lead wire 52 contacts the outlet pipe 44 at a spot weld i4. The same lead contacts one end Si of the windings 5l at 58, said lead 5I extending through an aperture in the wall of the annular member I2. Another lead i2 contacts the inlet pipe I4 at the spot weld i4 and it contacts the opposite end of the winding 52 at il. Said end passes through an aperture 'I0 in the wall of the annular member I2. The structure having been described, the operation will be readily understood. To start the pump it is primed by flooding the chambers 2l and 24 with liquid metal by methods conventional with centrifugal pumps. The electrical circuit is closed in order to energize the magnetic windings Il and to apply the D. C. potential between the inlet pipe I4 and the annular housing 2l. In this manner, a radial current is causedto flow between the inlet pipe I4 and the annular housing Il. as indicated by the double-headed arrows. Simultaneously the magnetic held, as indicated by the triangular-headed arrows is caused to flow through in a direction perpendicular to the chamber 28 and thus to the direction of the electrical current, said ileld being induced by the windings 5l. The conductlng metal is thus impelled by the interaction of the magnetic field and the current in a direction perpendicular to both. Within the chamber 24 the metal thus whirls about a path which is made spiral by centrifugal force until it is forced into the enlarged chamber 34 from which it flows through the outlet 44 which is tangentially disposed in the periphery of the chamber.

The foregoing description has been in reference to a single pump. The pump, however, ls well adapted to series or cascade connection, as shown schematically in Figure 3. In such connection, the outlet of one pump leads directly to the inlet of the second pump. and in order to avoid short circuiting. the single electrical contact 54 is provided thereon. By the same token the inlet of the first pump and the outlet of the second pump are wired with a potential opposite to that at Il. In this manner, a liquid metal can be pumped through a closed system which includes a heat exchanger 12. illustrated schematically in Figure 3, and which includes a heat source 1I, such as an atomic reactor, illustrated schematically in the same ligure.

The above description and accompanying drawings present a single embodiment oi' this invention.

What is claimed is:

1. An electromagnetic pump i'or electrically conductive fluids comprising, in combination, a partitionless disk-shaped chamber having side walls composed of insulating material and having an enlarged peripheral portion with side walls composed of conducting material and with an outlet suitably disposed therein, an inlet centrally disposed in the disk-shaped chamber with side walls composed of conducting material, a direct potential source between the peripheral portion and the inlet extending radially within the disk-shaped chamber, and means for creating a magnetic i'leld perpendicular of the chamber.

2. An electromagnetic pump for electrically conductive iluids comprising, in combination, a partitionless disk-shaped chamber having side walls composed oi insulating material and having an enlarged peripheral portion with side walls composed of conducting material with an outlet suitably disposed therein, an inlet centrally disposed in the disk-shaped chamber with side walls composed of conducting material, a direct potential source between the peripheral portion and the inlet extending radially within the disk-shaped chamber, and means for creating a magnetic ileld perpendicular of the chamber consisting of a magnet disposed on both sides of the disk-shaped chamber adjacent to the insulating material of the side walls.

3. An electromagnetic pump for electrically conductive fluids, comprising. in combination, a disk-shaped chamber having side walls composed of insulating material, an annular conduit peripherally disposed about said chamber composed of conducting material and having an outlet suitably disposed therein, the disk-shaped chamber having an inlet centrally disposed with side walls composed oi conducting material, a direct potential source between the annular conduit and the inlet extending radially within the disk-shaped chamber. and means for creating a magnetic ileld perpendicular of the chamber consisting of a magnet which surrounds the entire chamber. except for the inlet and the outlet, and which is separated from the annular conduit and from the central inlet by air gaps, and consisting of means for inducing the magnetic field therein.

4.1m electromagnetic pump for electrically conductive fluids comprising, in combination, a disk-shaped chamber having side walls composed of insulating material, an annular conduit peripherally disposed about said chamber comy posed of conducting material and havingan outlet suitably disposed therein, the disk-shaped chamber having an inlet centrally disposed with side walls composed oi' conducting material, a direct potential source between the annular conduit and the inlet extending radially within the disk-shaped chamber, and means i'or creating a magnetic iield` perpendicular of the chamber consisting of a magnet which surroimds the entirechambenexceptfortheinletandtheoutlet.andwhichiseparatcdiromtheannular conduit and from the central inlet by air gaps. and consisting oi' an annular channel for ileld windings within said magnet directly adjacent to the annular conduit, whereby said magnetic neld is induced.

5. An electromagnetic pump for electrically conductive Afluids comprising, in combination, a disk-shaped chamber having side walls composed oi' insulating material. an annular conduit peripherally disposed about said chamber and communicative therewith composed of conducting material and having an outlet suitably disposed therein. the disk-shaped chamber having an inlet centrally disposed with side walls composed of conducting material. a direct potential source between the annular conduit and the inlet extending radially within the disk-shaped chamber, and means i'or 'creating a magnetic field perpendicular ot the chamber consisting ot a magnet which surrounds the entire chamber. except for the inlet and the outlet, and which is separated from the Yannular conduit and from the central inlet by air gaps, and consisting of an annular channel for field windings within said magnet directly below the annular conduit. whereby the interaction o! the radial current in the transverse magnetic neld moves the conducting iluid in a direction normal to both the electric current and magnetic ileld, thereby whirling the fluid within the disk-shaped chamber until centrifugal action forces the fluid into the annular conduit and out the outlet.

6. An electromagnetic pump for electrically conductive iluids comprising. in combination, a disk-shaped chamber having side walls composed oi' insulating material, an annular conduit peripherally disposed about said chamber and communicative therewithcomposed of conducting material and having an outlet suitably disposed therein. the disk-shaped chamber having an inlet centrally disposed with aide walls composed ot conducting material, a direct potential source between the annular conduit and the inlet extending radially through the chamber.

' which source is supplied to the walls of the cutlet and discharged from the wall of the inlet. and means for creating a magnetic ileld pel'- pendicular of the chamber consisting of a magnet which surrounds the entire chamber. except for the inlet and the outlet, and which is separated from the annular conduit and from the central inlet by air gaD. and consisting of an annular channel for held windings within 'said magnet directly below the annular conduit, whereby the interaction of the radial current in the transverse magnetic neld moves the conducting fluid in a direction normal to both the electric current and magnetic field, thereby whirling the iluid within the disk-shaped chamber until centrifugal action forces the iiuid into the annular conduit and out the outlet.

FREDERICK E. CREVER.

References Cited in the ille of this patent UNITED STATES PATENTS Number Name Date 2,258,415 Lago Oct. 7, 1941 2,386,360 Thompson Oct. 9. 1945 2,397,785 Friedlander Apr. 2. 1046 FOREIGN PATENTS Number Country Date 528.001 Great Britain Oct. 22. i040 

